Unit of Observation
While the exact terminology Unit of observation is not always well know, it is a concept that all people who work with data has come across. Having an exact understanding of this concept and getting the habit of thinking about your data sets in terms if unit of observation is key to efficient structure
Read First
- Never trust the
Definition
The most common context where the concept of unit of observation is used is to describe a data set. A non-technical way to explain unit of observation in this context is what each row in the data set represents.
Methods to Explore the Unit of Observation in a data set
Look for duplicates. For example, after down
Usages other than in data sets
The examples below all have many similarities to how unit of observation is used in the context of a data set. They are included to give further explanation to the concept or highlight small differences in usage.
Regressions
The unit of observation in a regression is what the N (or number of observations) represents. That is very much related to how the concept is used in the data set, as the N is the number of rows from the data set included in the regression. To be able to interpret the regression correctly therefore depends on understanding the unit of observation. In most cases this is trivial, but we have had issues where regressions have been misinterpreted as a monitoring data that was believed to have the unit of observation "households", while it actually was "packages distributed to households". Since the vast majority of households only received one package each, it was easy to make this mistake than what it first might seem.
Surveys
The concept of unit of observation can also be used to describe for example surveys. The unit of observation in a survey is the type of respondent. For example, household, company, school etc. In the cases of company and school the respondent is a person, for example the CEO or the principal, but they provide answers about the company or the school. If they would be asked questions about themselves, then
Back to Parent
This article is part of the topic Data Management
Additional Resources
- list here other articles related to this topic, with a brief description and link